Method for finishing articles

ABSTRACT

A method for abrading and removing roughness from articles of manufacture by means of high temperature and shock waves. Unfinished articles are disposed in a reaction chamber and one or more shock waves are generated and directed against the surfaces of the articles to smoothen or finish same by heat and pressure. In one form, the articles may be stationary during the finishing operation. In another form, they may be tumbled or otherwise moved during or between the generation of shock waves. The process may be carried out with or without the presence of abrading particles in contact with the work.

nited States atent .1

Lemelson 1 Dec. 3, 1974 METHOD FOR FINISHING ARTICLES 2,591,083 4/1952 Maier 51/2 R 2,702,692 2 1955 K 1 51/010. 11

[76] Inventor: lemme Lemelsw 85 Rector Sta 2,714,563 8/1955 51/8 R x Metuchen, 088/40 2,826,369 3/1958 Haltmeier.... 241/1 ar. Segraves 211 Appl. No.: 238,362

Related U.S. Application Data [63] Continuation-impart of Ser. No. 93,779, Nov. 30, 1970, Continuation-impart of Ser. No. 668,567, June 27, 1957, abandoned.

[52] U.S. Cl. 51/319, 241/1 [51] Int. Cl. B24c 1/00 [58] Field of Search 51/59 SS, DIG. 11, 281 R,

Fruth ..;5l/D1G. 11

H1 VOLTAG E POWER SUPPLY PROGRAM CONTR Primary ExaminerDona1d G. Kelly [5 7] ABSTRACT A method for abrading and removing roughness from articles of manufacture by means of high temperature and shock waves. Unfinished articles are disposed in a reaction chamber and one or more shock waves are generated and directed against the surfaces of the articles to smoothen or finish same by heat and pressure. In one form, the articles may be stationary during the finishing operation. In another form, they may be tumbled or otherwise moved during or between the generation of shock waves. The process may be carried out with or without the presence of abrading particles in contact with the work.

13 Claims, 1 Drawing Figure TRIGGER SWITCH PATENTELBEE O 3,851,426

TRIGGER SWITCH 49 HI VOLTAG E POWER SUPPLY sOL-EWID COM BUSTI G AS SUPPLY PROGRAM CONTROL METHOD FOR FINISHING ARTICLES RELATED APPLICATIONS This is a continuation-in-part of copending application Ser. No. 93, 779 filed Nov. 30, 1970, for'Wave Generating Apparatus and Method having as a parent application Ser. No. 668,567 filed June 27, 1957, for Wave Generating Apparatus,'now abandoned.

SUMMARY OF THE INVENTION This invention relates to a method for operating on work such as articles of manufacture and the like required to be finished. In particular, the invention relates to a method for surface finishing work-in-process such as machined parts, casting, moldings and the like to remove surface roughness, flash and burrs. The method employes high pressures and temperatures generated by explosive reactions and shock waves in a chamber to finish and remove material from work.

Before the making of the instant invention, it was known in the art to surface finish, deflash or debur work by grinding particles at high velocity against the work. These methods contain certain shortcomings and disadvantages which include the time required to finish the work, the need for compleX conveying and discharge equipment and contamination of the work.

Accordingly, it is a primary object of this invention to provide a new and improved method for finishing material and work-in-process.

Another object is to provide a method for finishing work which is effective in a minimum amount of time for many finishing operations.

Another object is to provide a method for physically affecting material and changing its shape by means of shock waves.

Another object is to provide a method for deflashing or deburring machined and otherwise formed units of work-in process by means of the intense temperature and pressure generated by one or more shock waves.

Another object is to provide a method for working the surface of an article with shock waves.

With the above and such other objects in view as may hereafter more fully appear, the invention consists of the novel constructions, combinations and arrangements of parts as will be more fully described in the accompanying drawing, but it is to be understood that changes, variations and modifications may be resorted to which fall within the scope of the invention as claimed.

The drawing illustrates an apparatus fortreating or finishing articles such as moldings, castings or so called machined components produced by a variety of processes such as lathe turning milling, drilling and the like. The apparatus 10 includes a moveable reaction chamber 11 shown as having a circumscribing side wall 12, and end wall 13 at the upper end thereof and a flange 14 at the lower, open end of said chamber. Notation 15 refers to a lip seal formed in and protruding downwardly from the bottom face of the flange 14 which lip is operable to engage and effect a fluid pressure seal against the upper surface of a platen 37 supported on a bed 36 which provides the major support for the apparatus 10. Ordinarily one or more articles are disposed on the upper surface of platen 37 and are worked or finished after the chamber 11 is driven downwardly to seal the lip against the platen so as to totally enclose the interior volume 11V of the chamber and to permit substantial pressure and temperature to be generated therein by the means hereinafter described.

The chamber 11 is supported by shafts 31 and 33 of respective lineal actuators and 32 which may comprise air or hydraulic cylinders which are supported on a spider frame 29 secured to uprights 28 which are supported at their lower ends by the machine bed 36.

Extending through and secured within an opening in the upper wall 13 of the chamber 11 is an injection nozzle 22 for a combustable gas such as propane or other gas or vaporous fuel provided in a tank reservoir 26, the output line 26 of which is connected to a pump 24 having an output 23 connected to the nozzle 22. A pulse operated servo device 25 such as a solenoid or stepping motor, drives pump 24 each time it is actuated to force a predetermined quantity of combustible gas through line 23 and nozzle 22 into the interior volume 11V of chamber 111.

A plurality of electrodes 18 and 21 are supported across the chamber 11 near the upper end thereof within respective insulators l7 and 20 which are supported within holes extending through the side wall 12 of the chamber 11 and through tibular projecting portions 16 and 19 which are formed integral with or secured to said side wall. An electric arc may be made to discharge between the electrodes 18 and 21 when a switch 47 is closed by the operation of a solenoid 48. Closure switch 47 is operable to activate a source 49 of high voltage potential, theoutput of which high voltage source is operatively connected across the electrodes 18 and 21.

Auxilliary components of the apparatus 11 include the following. A sub platen 37' in the form of a piston is disposed within platen 37 and may be actuated to move up and down while the chamber 11 seals against the platen 37 for the purpose of moving one or more articles disposed on the upper surface of the sub platen to upwardly expose different surfaces of said articles. A lineal actuator 38 is mounted within a cavity of the bed 36 and has its output shaft 39 connected to the sub platen 37" such that when the actuator 38 is activated, it will move the sub platen in a quick up and down stroke to cause articles thereon to fall randomly on the sub platen.

A belt conveyor 41 is disposed at the side of the bed 36 and is operated by a control motor 42 to intermittently deliver one or more articles into alignment with the upper surface of platen 37. A controlled lineal actuator 43 is disposed in alignment with the upper surface of the belt of conveyor 41 and has an output shaft 45 connected to a pusher plate 46 which when the actuator is advanced, pushes the article or articles off the upper surface of the conveyor 41 onto the upper surface of platen 37 and, if the sub platen 37' is utilized, onto its upper surface. The actuator 43 may be operated in two modes, one to remove articles from the belt conveyor and push them onto the platen 37 and the other to push articles which have been processed, off the platen 37 onto a receiving chute 52 disposed in alignment therewith across the bed 36.

Notation 34 refers to a flexible metal hose connected to a source of particles or other material which may be desired to be injected into the volume 11V after the lip 15 is sealed against the upper surface of platen 37 for performing one or more functions as will be described.

While all of the described power operated switching devices may be individually or manually controlled to become operative and be deactivated, they are preferably under the control of a single master controller such as a programming device or multi-circuit timer 47 which, in perhaps its simplest form, may comprise a constant speed motor driven shaft with cams located and spaced apart intervals thereon which are operable to open and close respective switches gating electrical energy from a power supply 46 to the respective electrically operated solenoids and motors.

In a typical mode of operation, the timer 47 is set into operation by manually closing a switch 478 and the following sequence of operations occur as a result of signals generated on the plural outputs 47' of the timer. A first signal is generated and transmitted to the reverse control 32R for the linear actuators 30 and 32 which, when operated by said signal, cause the actuators to retract their outputs shafts 31 and 33 lifting the chamber 11 upwardly to clear the upper surface of platen 37. The forward input control 44F of lineal actuator 43 is then operated by a first signal generated by multi-circuit timer 47 which causes its shaft 45 to fully project across the upper surface of platen 37 causing its pusher plate 46 to sweep said upper surface clear of articles disposed thereon which are pushed onto the discharge chute 50. The reverse control 44R of actuator 43 then retracts shaft 45 to clear the upper surface of belt conveyor 41. The forward drive control 42F of conveyor motor 42 is then operated by timer 47 causing the conveyor belt to move a predetermined degree such that one or more articles disposed thereon are brought into alignment with the upper surface of platen 37. The stop control 428 of conveyor motor 42 is then pulsed by a signal generated by multi-circuit timer 47 stopping the belt with an article or articles aligned with the upper surface of platen 37. A second control 44F of lineal actuator 43 is next energized by a signal generated by timer 47 causing its shaft 45 to be projected and to slide the article or articles off the upper surface of conveyor 41 and center same directly beneath chamber 11. The reverse drive control 44R of lineal actuator 43 is then pulsed causing the shaft to retract out of the way of cylinder 41. The forward control 32F for the lineal actuators 30 and 32 is then pulsed causing their shafts 31 and 33 to be projected and moving flange 14 of chamber 11 to cause the circumscribing sealing lip 15 to engage the upper surface of platen 37 and to seal the chamber thereagainst.

Following the above steps is a processing step which may comprise either the operation of generating one or a plurality of shock waves within the volume 11V which shock waves are formed merely by generating an intense spark or sparks across the electrodes 18 and 21 or by exploding a gas admitted to chamber 11 either as a result of a single explosion or a plurality of such explosions. Operation may also consist of a series of shock waves which are generated by a combination of exploding gas and one or more high intensity sparks discharged between the electrodes without the phenomonon of gas burning.

The operation of the one or more shock waves on the exposed surfaces on the article or articles disposed within the chamber may be utilized per se to affect the articles in one or more manners which will be defined hereafter or may be combined with the action of one or more chemicals or particles injected into the chamber near the lower thereof through the flexible line 34 and opening 35 in the chamber wall by means of a solenoid valve 348, the solenoid of which is connected to one of the outputs 47 of the timer controller 47. The solenoid valve 345 connects flexible line 34 with a pressurized source 51 of the desired chemical or particle to be injected into the chamber volume 11V.

The control solenoid 48 for operating switch 47 to cause a high potential arc to develop acros's electrodes 18 and 21, is also operated by a signal generated by multi-circuit timer 47 in proper sequence with the other signals generated on respective outputs thereof, to effect the described operations.

Operation of the apparatus 10 may thus be effected in the following modes:

I. An article or articles disposed on the upper surface of platen 37 and confined within volume 11V may be surface finished by having surface roughness, flash, protuberance or burrs removed therefrom by the operation of one or more high intensity shock waves generated within the chamber by means of high potential electrical discharge across the electrodes 18 and 21 per se or generated by means of exploding a quantity of combustible gas admitted to the chamber. As stated, this first finishing operation may be effected by the intense force and temperature of a single shock wave or a plurality of shock waves which are generated in succession at a predetermined frequency within the volume llV.

ll. Surface treatment such as case hardening may be effected by the rapid heating and force applied to the surface of the article or articles by a single shock wave or plurality of such shock waves generated as described.

lll. Surface abrading of the article or articles disposed on the platen 37 may be effected by the operation of one or more shock waves reacting on either abrasive particles or small, hard balls or metal, glass or ceramic materials injected into the chamber after the lip 15 is sealed against the upper surface of platen 37, through the flexible line 34 as described. These particles or balls may be made to intermittently impact against the outer surface of the article or articles and to stress-relieve or peen the material of the surface stratum thereof as they are reacted on by the shock wave or shock waves generated within the chamber.

IV. A suitable material flowed through the flexible line 34 may be coated onto the surface or surfaces of an article or articles disposed on the upper surface of platen 37 after it is injected into the volume 11V through the flexible line 34 and inlet 35. The temperature and pressure of the shock waves may be utilized to coat said article or articles by heating the coating material and the surface of the article to effect a fusion bond between the two and, in certain instances, to heat treat the coating material after it is disposed on the article s surface. To prevent coating of such material on the upper surface of platen 37, said upper surface may be coated with a nonsticking material such as Teflon or a temporary sheet of material may be disposed thereon during each coating operation and removed after each operation or after it has been itself coated to a predetermined degree.

Thus it is seen that the apparatus may be operated in a plurality of modes which include the use of a single shock wave to a plurality of intermittently generated shock waves which are operable for performing one or more of the operations of surface smoothing, roughness reduction, eroding, deflashing, deburring, stress relieving, annealing, cladding, coating, plating or otherwise treating articles disposed within the reaction chamber as described. These operations may generally be referred to as surface finishing operations although the operation may also include internally improving the structure of the article being subjected to the force of the shockwaves such as improvement in the crystalline structure of the material thereof.

I claim:

1. A method for operating on and physically changing work-in-process comprising:

disposing an article to be physically worked in a confined reaction chamber,

generating a shock wave within said chamber of such an intensity to heat and apply sufficient force to the article to physically change the shape of the article located within said chamber, and

directing said shock wave against said article in a manner to cause said shock wave to react on the surface of said article so as to change the shape of said article and to alter the surface configuration thereof without destroying the integrity of the article whereby the article is surface finished.

2. A method in accordance with claim 1 which includes disposing an abrasive particulate material adjacent the surface of said article which abrasive particulate material is caused to react on said article under the influence of said shock wave wherein said shock wave is operable to simultaneously surface finish and change the shape of said article.

3. A method in accordance with claim 1 wherein the shock wave is generated by exploding a gas within said chamber.

4. A method in accordance with claim 1 wherein the shock wave is generated by discharging an intense electrical spark within said chamber.

5. A method in accordance with claim 1 wherein the shock wave is generated while the chamber is closed confining the force and heat of the shock wave thereto.

6. A method in accordance with claim 1 wherein the article contains protuberances of substantially smaller cross section than the body of the article and said shape changing is accomplished by removing at least certain of said protuberances from the main body of the article.

7. A method in accordance with claim 1 including the further step of disposing an abrasive medium composed of particles between the surface of the article and of the source of said shock wave to be acted upon by said shock wave whereby the shock wave, in addition to reacting on the article, also causes the particles to react on the surface of the article so as to finish the material defining said surface.

8. A method in accordance with claim 7 wherein said abrasive medium and said shock wave are operable to remove material from the surface of the article.

9. A method in accordance with claim 8 wherein the article surface contains a plurality of proturbances and said shockwave and abrasive medium are operable to remove the protuberances from the article.

10. A method in accordance with claim 1 including generating a plurality of shock waves within said chamber, in succession and of such intensity to incrementally change the shape of the article disposed in the chamber.

11. A method of operating on work-in-process comprising:

disposing an article to be surface finished in a confined reaction chamber,

generating a high intensity shock wave within said reaction chamber, and

directing said shock wave against the surface of said article in a manner to erode and remove material from said article so as to surface finish the article.

12. A method in accordance with claim 11 wherein the erosion of the article and removal of material therefrom is effected by both the heat and force of said shock wave applied to the surface of said article.

l3. A method in accordance with claim 12 which includes generating a plurality of shock waves within said chamber and successively applying said shock waves to the surface of said article to progressively erode material therefrom. 

1. A method for operating on and physically changing work-inprocess comprising: disposing an article to be physically worked in a confined reaction chamber, generating a shock wave within said chamber of such an intensity to heat and apply sufficient force to the article to physically change the shape of the article located within said chamber, and directing said shock wave against said article in a manner to cause said shock wave to react on the surface of said article so as to change tHe shape of said article and to alter the surface configuration thereof without destroying the integrity of the article whereby the article is surface finished.
 2. A method in accordance with claim 1 which includes disposing an abrasive particulate material adjacent the surface of said article which abrasive particulate material is caused to react on said article under the influence of said shock wave wherein said shock wave is operable to simultaneously surface finish and change the shape of said article.
 3. A method in accordance with claim 1 wherein the shock wave is generated by exploding a gas within said chamber.
 4. A method in accordance with claim 1 wherein the shock wave is generated by discharging an intense electrical spark within said chamber.
 5. A method in accordance with claim 1 wherein the shock wave is generated while the chamber is closed confining the force and heat of the shock wave thereto.
 6. A method in accordance with claim 1 wherein the article contains protuberances of substantially smaller cross section than the body of the article and said shape changing is accomplished by removing at least certain of said protuberances from the main body of the article.
 7. A method in accordance with claim 1 including the further step of disposing an abrasive medium composed of particles between the surface of the article and of the source of said shock wave to be acted upon by said shock wave whereby the shock wave, in addition to reacting on the article, also causes the particles to react on the surface of the article so as to finish the material defining said surface.
 8. A method in accordance with claim 7 wherein said abrasive medium and said shock wave are operable to remove material from the surface of the article.
 9. A method in accordance with claim 8 wherein the article surface contains a plurality of proturbances and said shockwave and abrasive medium are operable to remove the protuberances from the article.
 10. A method in accordance with claim 1 including generating a plurality of shock waves within said chamber, in succession and of such intensity to incrementally change the shape of the article disposed in the chamber.
 11. A method of operating on work-in-process comprising: disposing an article to be surface finished in a confined reaction chamber, generating a high intensity shock wave within said reaction chamber, and directing said shock wave against the surface of said article in a manner to erode and remove material from said article so as to surface finish the article.
 12. A method in accordance with claim 11 wherein the erosion of the article and removal of material therefrom is effected by both the heat and force of said shock wave applied to the surface of said article.
 13. A method in accordance with claim 12 which includes generating a plurality of shock waves within said chamber and successively applying said shock waves to the surface of said article to progressively erode material therefrom. 